During operation, semiconductor components are heated because of high current densities with a high voltage at the same time. Such heating can either be comparatively homogeneous, or locally restricted, because of current filamentation.
When semiconductor components are operated below the so-called stable-temperature point, current filamentation may occur at a sufficiently high voltage, and can lead to destruction of the semiconductor component.
Therefore in order to prevent excessive heating and current filamentation, the electrical parameters such as the forward current, dl/dt, dU/dt, temperature etc. are generally limited appropriately, in order not to exceed the safe range (SOA range) during operation. On the one hand, this restricts the possible improvement of the semiconductor component characteristics, and on the other hand, the options for use of the semiconductor components are limited, particularly when disturbances are taken into account which require the semiconductor components to be more robust.
One possibility to protect semiconductor components against excessive heating is to install one or more temperature sensors in the semiconductor component and to regulate the gate voltage of the semiconductor component down to a lower value, beyond a specific threshold temperature, on the basis of the measurement results from the temperature sensors. However, this results in increased complexity both in the semiconductor component and for the temperature evaluation and the regulation of the gate voltage. Further, a certain delay time in the temperature signal must be expected, because of the physical distance between the temperature source and the temperature sensor.